氨气在内燃机中的应用与NO_x排放控制技术

田杰¹，熊勇²，程勇^1*，王兆宇³

1.山东大学核科学与能源动力学院，山东 济南  250061；

2.比亚迪汽车工业有限公司汽车工程研究院，广东 深圳  518119；

3.龙口中宇热管理系统科技有限公司，山东 龙口  265700

摘要：针对氨气燃烧时存在的点火困难、火焰速度低、可燃性范围窄、NO_x排放高的问题，综述氨燃料特性及制备方法，总结氨气在内燃机上的应用，分析氨气燃烧产生NO_x排放的机理，探讨降低NO_x排放的措施，并提出氨燃料内燃机的发展方向。结果表明：氨燃料的自燃温度较高，火焰传播速度较慢，点火延迟较长，通过优化燃烧控制以及与其他燃料的混合，能够提高其燃烧性能并减少环境污染；氨气可以通过化学合成、生物质转化和水的电解等多种方法生产，电化学合成氨是目前最有前途的合成氨气途径之一；混合燃烧和富氧燃料可以提高氨气的燃烧速度；氨燃烧时产生的NO_x主要来自氨气中的氮元素，通过选择性催化还原、分级燃烧、中度或高强度低氧稀释燃烧等技术，可以显著减少氨燃料燃烧过程中NO_x排放，改善氨气燃烧对环境的影响。

关键词：氨燃烧；内燃机；燃烧特性；NO_x排放

Overview of the application of ammonia in internal combustion engines andNO_xemission control technologies

TIAN Jie¹, XIONG Yong², CHENG Yong^1*, WANG Zhaoyu³

1. School of Nuclear Science, Energy and Power Engineering, Jinan 250061, China;

2. BYD Automotive Industry Co., Ltd., Shenzhen 518119, China;

3. Longkou Zhongyu Thermotech Co., Ltd., Longkou 265700, China

Abstract: In response to the problems of ignition difficulty, low flame speed, narrow flammability range, and high NO_x emission during ammonia combustion, this paper reviews the characteristics and preparation methods of ammonia fuel, summarizes the application of ammonia in internal combustion engines, analyzes the mechanism of NO_x emission generated by ammonia combustion, explores measures to reduce NO_x emission, and proposes the development direction of ammonia fuel internal combustion engines. The results show that ammonia fuel has a higher self-ignition temperature, slower flame propagation speed, and longer ignition delay. By optimizing combustion control and mixing with other fuels, the combustion performance can be improved, and environmental pollution can be reduced. Ammonia can be produced through various methods, such as chemical synthesis, biomass conversion, and water electrolysis. Electrochemical synthesis of ammonia is currently one of the most promising pathways for ammonia synthesis. Mixing combustion and oxygen-enriched fuel can increase the combustion rate of ammonia. The NO_x generated during ammonia combustion mainly comes from the nitrogen element in ammonia gas. Through technologies such as selective catalytic reduction, staged combustion, moderate or intense low-oxygen dilution combustion, NO_x emission during ammonia fuel combustion can be significantly reduced, and the environmental impact of ammonia combustion can be improved.

Keywords: ammonia combustion; internal-combustion engine; combustion characteristics; NO_x emission